Hello,
I am trying to use the Save function in the EasyChart to download historical logs from my trends for safe keeping, but I am running into issue of the Excel download has too many lines for the information I am trying to download.
Assuming I am doing this correctly, I have the tag group to collect data every 500ms in Direct mode (Modified the Default tag group)
I also go to each tag that I want to collect data and enable history on it, setting it to 500ms max time between samples and sample rate of 500ms
the issue I am running into is that when I download an excel log from historical view, for each second, I get multiple lines in the log where it should just be 1 line per second, or 2 lines since it is 500ms data capture rate.
The easy chart's default tag history resolution mode adds one data point to its dataset for every displayed pixel, so if a tag with a poll rate of 2 per second only covers 250 data points in a given domain bounds and there are 1500 pixels from left to right displayed, each of the data points will get duplicated to fill the space. The export doesn't take this into account when it exports the displayed data in the chart, so many duplicate entries end up in the set. The opposite would be true if the date range covered more data points than there are pixels. In that case, data points would be omitted from the set.
To get precise data point exports for a given domain, the tag history resolution would need to be set to raw data, but it's possible that this will have an undesirable impact on how the chart renders. The alternative would be to overlay a custom save button that does its own tag history query to retrieve the raw data for the chart's displayed domain, and then, export the resultant dataset to excel.
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